# 函数递归
def range_sum(begin, end):
	start = begin
	if begin != end - 1:
		return start + range_sum(begin + 1, end)
	return end - 1


def fib_num(n):
	if n == 0:
		return 0
	if n == 1 or n == 2:
		return 1
	return fib_num(n - 1) + fib_num(n - 2)


print(range_sum(1, 5))
print(fib_num(60))#1 1 2 3 5
